Capacitive fingerprint sensor for real-time identification of fingerprint, inputs pulse control voltage to signal reading circuit comprising shutter switch to enable sense and reference capacitors to share charges

摘要

The sensor (2) has a two-dimensional array of capacitive sensing elements (20) covered by an insulating layer. Each capacitive element has a signal reading circuit with a shutter switch to control connection between sense and reference capacitors. A basic peripheral circuit inputs pulse control voltage to signal reading circuit to enable sense and reference capacitors to share charges to read sense signals.